There is wide discussion about the association between sport activity and musculoskeletal disorders, as sports-related joint loading increases the risk of osteoarthritis (OA). The present article reviews the current available literature on the connections between participation in several sports and athletic activities and prevalence of knee OA, especially focusing on early knee OA. The study was based on an electronic search through web databases including Medline, Cochrane and Google Scholar. Articles were retrieved and evaluated, and case series, retrospective studies, case-control studies, prospective cohort studies and randomized controlled trials were considered for inclusion. The main data were extracted and summarized in tables and text. Athletic individuals do show an increased prevalence of knee OA, especially for professional athletes when compared to general population or non-professional athletes. Furthermore, several features related to sport activity were associated to increased risk of early knee OA, such as knee ligamentous injury, concussion, high-impact sports and different team roles. Methodology and results of the included studies are barely comparable, thus preventing the authors to carry out an accurate and systematic comparison of the results of the included studies. Only low level evidence studies are available, and better designed studies, with radiological and functional evaluation of the knee based on internationally validated measures, should be planned. Also, follow-up of patients during and after their life-period of sport involvement should be considered.
Keywords: athletes; injury; knee; osteoarthritis; sport; sport medicine.